There are known in the prior art various forms of sound attenuating earcup assemblies which are designed to protect the wearer's hearing against damage as a result of ambient noise. One of the difficulties which has been encountered with such assemblies is that they do not permit of a direct outside communication with persons in the surrounding area without removing the protective earcup assemblies from the wearer's head. Attempts have been made in the prior art to solve this problem.
Wood U.S. Pat. No. 3,306,911 represents one attempt to solve the problem outlined above. This patent shows a protective earcup assembly in which an external shell made from metal, fiberglass or plastic, or the like, has a peripheral cushion seal for engaging the wearer's head and a liner formed from a sound absorbing material such, for example, as foamed plastic. A miniature speaker is embedded in the liner. A mounting bracket on the outside of the rigid cup carries a housing for the amplifier, which housing supports a microphone and a combination on/off and volume control switch. This housing which is of generally rectangular configuration extends an appreciable distance outwardly of the outer surface of the earcup. A door is provided for access to the interior of the housing for replacement of the battery. An electrical lead extends through the cup and its liner to the receiver.
While the arrangement shown in the Wood patent apparently successfully achieves the functional result of permitting a person wearing a protective earcup to communicate with persons in the surrounding area without the necessity of removing the earcup, structurally it leaves much to be desired. First, it is extremely bulky for the result achieved thereby. The housing extends outwardly of the cup for such an extent that it is likely to come into contact with surrounding objects as the wearer moves his head, particularly in relatively close quarters. It requires the electrical lead to be passed through the hard outer shell in some undisclosed manner. The arrangement does not permit of the ready replacement of various components of the system.